The present invention relates to an improvement in a synthetic-speech calculator.
A synthetic-speech calculator is well known in the art of calculators. The prior art synthetic-speech calculators were capable of adjusting the volume of audible sounds through the use of a knob. Once the adjusting knob was set, the intensity of the audible sounds was constant in spite of the purpose of the audible sound. It is, however, desirable to the operator that audible sounds representative of calculation results be loudly produced while audible sounds concerning the entry of information from the keyboard be of lesser intensity. On the contrary, it is sometimes desirable that audible sounds be amplified only during the operation of keys in order to avoid errors in the entry of information while calculation results are visually provided. It may be more desirable to suppress the generation of audible sound in certain circumstances.
Meanwhile when producing audible sounds representative of the operation of a specific key, the operation of a next succeeding key should discontinue the generation of the previous audible sound. Accordingly, rapid operation of the keyboard causes a discontinuity in the production of audible sounds. If the operator is allowed to operate a specific key only after the delivery of audible sounds concerning the preceeding operated key, limitations on the speed of key operations would be unavoidable.